Hot Rolled Steel Sheet

Abstract: This hot rolled steel sheet has a prescribed chemical composition. If a region corresponding to 1/8 to 3/8 of the sheet thickness in the sheet thickness direction from the surface is defined as the 1/4 depth position, the metal structure at the 1/4 depth position contains less than 3.0% of retained austenite, less than 30.0% of ferrite and less than 5.0% of pearlite in terms of areal ratio. At the 1/4 depth position, the average density by number of Ti-based carbides having lengths of 15 nm or more is 1.0×104 carbides/mm2 or more. The average crystal grain diameter dq is 15.0 µm or less, and a tensile strength is 980 MPa or more.

Patent Information

Application #

Filing Date

01 February 2024

Publication Number

11/2024

Publication Type

INA

Invention Field

METALLURGY

Status

Email

Parent Application

Applicants

NIPPON STEEL CORPORATION

6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071

Inventors

1. YOSHIDA Mitsuru

c/o NIPPON STEEL CORPORATION, 6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071

2. HIKIDA Kazuo

c/o NIPPON STEEL CORPORATION, 6-1, Marunouchi 2-chome, Chiyoda-ku, Tokyo 1008071

Specification

Documents

Application Documents

#	Name	Date
1	202417006687-TRANSLATIOIN OF PRIOIRTY DOCUMENTS ETC. [01-02-2024(online)].pdf	2024-02-01
2	202417006687-STATEMENT OF UNDERTAKING (FORM 3) [01-02-2024(online)].pdf	2024-02-01
3	202417006687-PROOF OF RIGHT [01-02-2024(online)].pdf	2024-02-01
4	202417006687-PRIORITY DOCUMENTS [01-02-2024(online)].pdf	2024-02-01
5	202417006687-POWER OF AUTHORITY [01-02-2024(online)].pdf	2024-02-01
6	202417006687-FORM 1 [01-02-2024(online)].pdf	2024-02-01
7	202417006687-DRAWINGS [01-02-2024(online)].pdf	2024-02-01
8	202417006687-DECLARATION OF INVENTORSHIP (FORM 5) [01-02-2024(online)].pdf	2024-02-01
9	202417006687-COMPLETE SPECIFICATION [01-02-2024(online)].pdf	2024-02-01
10	202417006687-FORM 18 [07-08-2025(online)].pdf	2025-08-07